Kurdish fighters take control of Iraq's Sinjar

The offensive in Sinjar has cut off the ISIL's supply lines between their strongholds of Mosul in Iraq and Raqqa in Syria [Ari Jalal/Reuters]

Kurdish Peshmerga forces have entered the centre of Sinjar after pushing out Islamic State of Iraq and the Levant (ISIL) fighters from the northern Iraqi town, sources told Al Jazeera.

Sporadic bursts of gunfire could be heard inside Sinjar on Friday as Kurdish fighters filed down the hill overlooking the town from the north - some with rocket-propelled grenades on their shoulders, a witness told Reuters news agency.

However, Al Jazeera's Imran Khan, reporting from Sohela along one of the main supply routes for the Sinjar offensive, said the Peshmerga walked into town almost unopposed.

"The Kurdish Peshmerga entered the town from the north this morning [Friday] and took over the municipal building there. They now say they are in control of the entire town.

"We were expecting a fightback from ISIL. That hasn't happened. The Kurdish Peshmerga managed to walk into the town almost unopposed after intense fighting on Thursday. And that is actually quite unusual.

"We have seen ISIL when they are on the back foot fight back quite hard in the past. But pro-ISIL sources told me that most of the ISIL rebels had left Sinjar on November 11, in what they said was a tactical withdrawal," our correspondent said.

Backed by US-led air strikes, the Kurds cut Sinjar off from the east and west on Thursday in an offensive that could provide critical momentum in efforts to defeat ISIL.

The offensive in Sinjar has cut off the ISIL's supply lines between their strongholds of Mosul in Iraq and Raqqa in Syria and allowed Sinjar to be reconnected with the rest of northern Iraq.

The area of Sinjar, inlcuding Sinjar Mountain was overrun by ISIL in August last year in an onslaught that caused the flight of tens of thousands of Kurdish-speaking Yazidis, and first prompted the US to launch air strikes against ISIL.

The group launched a wave of attacks against the minority Yazidi community -members of an ancient religion whom ISIL views as heretics and accuses of worshipping the devil.

The Yazidis fled into the mountains where ISIL fighters surrounded them, trapping and exposing them to the blazing heat.

The crisis prompted the US to launch air drops of aid, and on August 8, 2014, it began its first round of air strikes in what would mark the beginning of a broader coalition effort to battle the group in Iraq and Syria.

Various Kurdish militias on the town's edge have been fighting guerrilla battles for months against ISIL fighters in Sinjar.

The factions include the Turkey-based Kurdish Workers' Party (PKK), the Syria-based People's Protection Units - better known as the YPG - and Yazidi-led forces calling themselves the Sinjar Resistance.